Never heard of an 'anti-ice filter' as part of a fuel system - heat exchangers to cool oil with fuel or heat fuel with oil yes - just how would this 'anti-ice filter' work as part of the fuel system?
If you remove the IBF from the 145, are you allowed to fly in falling and recirculating snow?
Protecting helicopter engines from snow is difficult - you can have heated intakes or put complex filtering arrangements or both but if the snow is wet and sticky, it is nigh on impossible to stop accumulations blocking the intakes.
If you allow snow to build up around the intake, then you have the problem Shy Torque mentions, the engines suddenly ingesting a 'mouthful' of snow which can easily put out the flame.